                   (ex-info "start-system! failed and unwound"
                            {:state st
                             :error e})))))))))
+(defn- system-map*
+  [system]
+  (filter-system-map system))
 
 (defn system-map
   "given the result of a config-ctx value fn,

  (d/chain
   dsys
   (fn [[_ system]]
     (let [sd (system-destructor system)]
       (run-state sd system)))))

(defn start-system!
  "given a system-builder, start a system with the seed config

  (d/chain
   dsys
   (fn [[_ system]]
     (system-map* system))))

(comment
  (require '[deferst.system :as dfs])
